A) Field of the Invention
The present invention relates to a lighting fixture that includes an electrodeposition device.
B) Description of the Related Art
A vehicle lighting device that efficiently notifies a driver of the presence of an illumination target such as a pedestrian is disclosed (see Japanese Unexamined Patent Application Publication No. 2008-120162).
A headlight used in a vehicle lighting device disclosed in Japanese Unexamined Patent Application Publication No. 2008-120162 is configured of, for example, a digital micromirror device (DMD). The DMD is a device that includes multiple micromirrors and can control the rotation of each of the multiple micromirrors. Since the rotation of the micromirror is performed using mechanical means, the headlight disclosed in Japanese Unexamined Patent Application Publication No. 2008-120162 has a problem in that the device is vulnerable to vibration, has low durability, it is difficult to achieve miniaturization or thinness, or the like. In addition, since the headlight disclosed in Japanese Unexamined Patent Application Publication No. 2008-120162 uses a perfectly reflective optical system, light loss due to reflection, and further, light loss due to aperture ratio is great. In the headlight disclosed in Japanese Unexamined Patent Application Publication No. 2008-120162, it is considered that light use efficiency is practically less than 70%.
An electrochromic device has been known as a nonradiative device that uses a color variation phenomenon of a substance by an electrochemical reversible reaction (electrolytic oxidation reduction reaction) when a voltage is applied.
Among electrochromic materials (materials that have a electrochemical oxidation or reduction reaction when a voltage is applied and thereby, have color variation such as coloring or decoloring), a material of which a part is, for example, precipitated or deposited (electrodeposited) on an electrode, or disappears from an electrode by an oxidation or reduction reaction is referred to as an electrodeposition material. In addition, a device that uses the electrodeposition material is referred to as an electrodeposition device.
An electrodeposition device that has a high quality mirror state is disclosed (see Japanese Unexamined Patent Application Publication No. 2012-181389). The electrodeposition device includes, for example, an electrolyte layer that contains a silver complex, and realizes the mirror state by applying a voltage and causing silver to be precipitated on an electrode. Further, the electrolyte layer contains, for example, copper. The electrodeposition device realizes a transparent state when no voltage is applied.